WO2023174242A1

WO2023174242A1 - System for lubrication in a gearbox for a vibration exciter

Info

Publication number: WO2023174242A1
Application number: PCT/CN2023/081243
Authority: WO
Inventors: Xianwang Li; Jingfeng Wang; Benjamin Edgar WEBER
Original assignee: Schenck Process (Tianjin) Industrial Technology Co. Ltd.
Priority date: 2022-03-16
Filing date: 2023-03-14
Publication date: 2023-09-21
Also published as: CN116804437A

Abstract

The specification relates to a bearing lubrication system (80) for a gear arrangement (40) including at least one gear (5, 6) carrying shaft (22, 23) supported by a bearing mounted in a bearing (27) mounting cavity (52) forming part of a housing (11) of the gear arrangement, the bearing lubrication system including a liquid lubricant collection zone positioned to collect liquid lubricant dispersed by a said gear passing through a main first liquid lubricant pool (42) in the housing, the bearing lubrication system further including weir means (53) partially closing the bearing mounting cavity to establish a liquid pooling zone in the bearing mounting cavity, the bearing lubrication system further having a liquid lubricant flow path from the liquid lubricant collection zone to the liquid pooling zone (51).

Description

SYSTEM FOR LUBRICATION IN A GEARBOX FOR A VIBRATION EXCITER

Field of the Invention

This disclosure relates to an improved system for lubrication of bearings used in a gearbox for a vibration exciter intended for use in mineral processing or handling equipment. Such vibration exciters are often utilised in ore and coal mining industries, as well as quarrying industries, but other comparable uses are also applicable.

The disclosure, of course, also relates to vibration exciters incorporating an improved bearing lubrication system in a gearbox forming part of the vibration exciter

Background of the Invention

A vibration exciter of the above discussed type typically includes a gearbox having a cast gearbox housing with a lower base wall, two upstanding side walls and two upstanding end walls defining an internal, generally open space, to receive at least two intermeshing gear wheels. The internal open space is closed by an upper wall releasably and sealingly secured to the upper edges of the side walls and the end walls. Each of the side walls has at least one integrally formed bearing housing part into which a bearing member is inserted to carry a shaft which also carries one of the gear wheels located in the internal space of the gearbox housing. The or each shaft carrying a gear wheel also extends outwardly through a cover member closing an outer open face of each bearing housing such that the portion of the or each shaft external of the or each cover member carries, in use, an eccentric weight or mass such that rotation of the shaft by any suitable drive means causes a desired vibration regime that can be imposed on desired equipment such as a screening deck or similar, utilised in mineral processing or handling equipment. It is reasonably common practice for each bearing in such equipment to be lubricated by providing a pool of lubricating liquid in the base of the internal open space in the gearbox housing which is, in use, engageable by at least one rotating gear wheel to cause some degree of lubricant spray to carry lubricant liquid to the shaft supporting bearings.

A number of practical difficulties have been recognised with the use of vibration exciters of the above discussed type. It is relatively common practice for such vibration exciters to be installed on the equipment to be vibrated at a reasonably steep inclination angle, for example, up to 45° or larger. This causes the liquid lubricant to pool at one end of the internal space within the gearbox housing. So long as a gear wheel passes through this pool, some splash lubrication will occur, particularly with the lower located bearings, however, it has been found that the more upwardly located bearings may not receive enough liquid lubricant and these bearings are at risk of relatively early failure. It is also usual for bearings in the above discussed type of gearbox to have a two roller ring array, that is an inner and an outer ring of roller members. It has been found that the outer ring of roller members may not receive enough liquid lubricant simply from conventional splash lubrication methods and, as a result, this may also be a possible factor that limits life of a bearing in such equipment.

In addition, the recent trends appear to be to use ever larger vibration exciters on mineral processing and handling equipment. This trend, however, seems also to have an adverse effect on bearing life. Still further, the above discussed difficulties with bearing life, appear to be more prevalent at start up of the apparatus when splash lubrication effects are likely to be at a minimum.

In light of the above discussion, it is generally recognised that an improvement to the lubrication levels of bearings used in this equipment would be desirable, both to improve their performance and to extend operational life between maintenance service stages. One such proposal to improve delivery of liquid lubricant to the bearings in such equipment is disclosed in International Patent Specification No WO2017/016665 A1. In this proposal, a series of axially outwardly extending pockets or recesses are provided extending from the inner edge face of the bearing housing, the pockets being intended to collect liquid lubricant and to deliver any such collected liquid lubricant to an inwardly located distributor ring positioned adjacent an inner face of the bearing with such liquid lubricant being forced into the rolling elements of the bearing.

An objective of the present disclosure is to provide lubrication arrangements in a gearbox for a vibration exciter to improve the effective level of liquid lubricant flow to the bearings used in such a gearbox and thereby provide an improvement in working life of the vibration exciter. A further preferred objective is to enable better lubrication of bearings at start up and restart up of such equipment. A further aim is to provide an improved vibration exciter utilising such an improved gearbox lubrication system.

Brief Summary of the Invention

In accordance with a first aspect of this disclosure, a bearing lubrication system is provided for a gear arrangement including at least one gear carrying shaft supported by at least one bearing mounted in a bearing mounting cavity of bearing mounting means forming part of a housing of said gear arrangement, said gear, in use, being rotatable through a first pool of liquid lubricant carried within said housing, said bearing lubrication system being characterised by: a liquid lubricant collection zone positioned internally of said housing to collect liquid lubricant dispersed by said gear passing through said first pool of liquid lubricant; a liquid lubricant weir means closing, at least partially, said bearing mounting cavity, whereby a liquid pooling zone is formed in a lower region of said bearing mounting cavity; and a liquid lubrication flow path enabling collected liquid lubricant from said liquid lubricant collection zone to flow from said liquid lubricant collection zone to said liquid pooling zone to form in said liquid pooling zone, a second pool of liquid lubricant.

In a particularly preferred embodiment, the bearing mounting cavity of said bearing mounting means includes an external opening closed, in use, by a cover plate member through which said gear carrying shaft passes to a position external of said housing, said liquid lubricant flow path including a first passage section passing from said first liquid lubricant collection zone in an outward direction, the liquid lubricant path further including a downward direction section either between the cover plate member and said bearing or through said cover plate member to be disposed in said bearing mounting cavity.

Conveniently, the gear arrangement includes a pair of gear carrying shafts with the gears intermeshing within an internal space of the housing, the shafts being rotatably supported by respective said bearings positioned in a said bearing mounting cavity of a said bearing mounting means located in opposed side walls of said housing of the gear arrangement. Preferably, the first pool of liquid lubricant is positioned in a lower region of the housing whereby, depending on the inclination orientation of the housing when installed in a use position, at least one of the intermeshing gears is partially immersed in the first pool of liquid lubricant. Thus, upon rotation of the gears, the gear that is partially immersed carries liquid lubricant to the second intermeshing gear and both gears cause a liquid lubricant spray dispersion, directed generally in the gear rotation direction. This spray dispersion mostly impinges on upper regions of the internal wall surfaces of the end and side walls of the housing, and on the internal surface of a closure (lid) wall of the housing. The liquid lubricant collection zone is positioned to collect as much of this liquid lubricant spray dispersion as it attempts to gravitationally flow from internal housing surfaces impinged back to lower regions in the housing. The present disclosure has application to a variety of gear arrangements including the two intermeshing gears carried on shafts discussed above and hereafter as well as a single gear carrying shaft and more than two gear carrying shafts. Generally, the shaft or shafts may extend externally of the housing and may carry eccentric and adjustable weights or masses to enable, in use, the imposition of a desired vibration regime to mineral processing or handling equipment, or other comparable use equipment.

In a preferred arrangement, the liquid lubricant collection zone may include a first zone section formed by an internal surface of a wall of said housing, and a pair of upstanding wall portions extending inwardly from said internal surface zone, said pair of upstanding wall portions converging towards one another in a V-configuration in a direction generally towards the bearing mounting means, and said liquid lubricant flow means includes a first flow passage leading outwardly through said wall of said housing from a location adjacent an apex of said V-configuration.

Conveniently, the liquid lubricant collection zone includes a second zone section having a liquid collection plate surface disposed generally axially relative to the gear carrying shaft, said liquid collection plate surface being spaced from said upstanding wall portions of said first zone section and is configured to deliver collected liquid lubricant therefrom to said first zone section. Preferably the collected liquid lubricant is delivered from an end edge of the liquid collection plate surface.

Preferably, the housing of the gear arrangement has opposed side walls with a said bearing mounting means and a said bearing mounted in a said bearing mounting cavity being located in each side wall, said gear carrying shaft passing through a said cover plate member closing each said bearing mounting cavity, said second zone section having a liquid collection plate surface extending axially between positions adjacent to and spaced from said side walls. Conveniently the second zone section is mounted to an inner surface of an upper closure wall or lid of the housing.

The present disclosure, of course, also anticipates providing a vibration exciter including a gear arrangement and bearing lubrication system according to any of the proposed arrangements outlined in the preceding paragraphs, the or each said gear carrying shaft also carrying one or more eccentric masses externally of the housing.

It should be further understood that any terms, if used, such as "comprises" , "comprising" , “includes” , “including” , “have” , and or “having” , specify the presence of stated features, items, steps, operations, elements, materials and or components, but do not preclude the presence of, or addition of, one or more other features, items, elements, components, materials, steps, operations and/or groups thereof.

Brief Description of the Drawings

Fig 1 is a partially exploded perspective view of a prior art exciter apparatus including a gear arrangement;

Fig 2 is a top plan view of the prior art apparatus shown in Fig 1;

Fig 3 is a section view of the prior art apparatus shown in Fig 2 take along line III-III;

Fig 4 is a section view of the prior art apparatus shown in Fig 2 taken along line IV-IV;

Fig 5 is a longitudinal section view of apparatus similar to Figs 1-4 but showing a bearing lubrication system in accordance with this disclosure;

Fig 6 is a detail section view of the bearing lubrication system zone shown in Fig 5 taken axially through the gear carrying shaft;

Fig 7 is a further detail section view similar to Fig 6 showing details of the liquid lubricant collection region and flow path omitting the liquid lubricant;

Fig 8 is a detailed perspective section view similar to Fig 5 but showing details of the liquid lubricant collection region; and

Fig 9 is a detailed perspective view similar to Fig 8 but including a representation of the collected liquid lubricant.

Detail of Preferred Embodiments

Figs 1 to 4 illustrate a prior art vibration exciter 10 for imposing a vibration regime to mineral processing or handling equipment. The vibration exciter 10 includes a gear arrangement with a cast housing 11 with opposed side walls 12, 13, opposed end walls 14, 15, and a closed base wall 16. The upper face of the cast housing 11 is substantially open with a surrounding seal flange, the upper face being, in use, closed by a top wall closure plate 17, a seal gasket 18 and a plurality of fasteners 19. Each of the side walls 12, 13 have adjacent openings 20, 21 to allow a long driven shaft 22 and a short driven shaft 23 to project therethrough when assembled. The driven shafts 22, 23 are carried by bearings 27 inserted into a bearing mounting cavity 8 in a bearing mounting structure 9 forming integral parts of the side walls 12, 13. The bearings 27 are typically spherical roller bearings (SRB) which include inner and outer rings of roller members. A pair of intermeshing gears 5, 6 are mounted for rotation with each driven shaft 22, 23 with the gears 5, 6 being located within space in the cast housing 11. In the assembled structure, the vibration exciter 10 includes eccentric masses 24 connected to outboard ends of the shafts 22, 23, that is, outwardly of the side walls 12, 13. Various arrangements of the eccentric masses are possible. Each of the outer openings 20, 21 in the bearing mounting structures 9 are closed by closure plates 25, 26 that are sealed to the side walls 12, 13 and include seals on the shafts 22, 23. The interior of the exciter housing 11, in its lower regions, provides a liquid lubricant zone or sump for maintaining a pool of liquid lubricant therein introduced through an upper opening 30 and drained therefrom, when needed, through a lower opening 31. Each of the bearings 27 and the gears 5, 6 are intended to be lubricated by passage of at least one of the gears 5, 6 through the liquid lubricant pool in the lower liquid lubricant sump or zone and by dispersal of splashed liquid lubricant from the lower liquid lubricant sump or zone by this gear passage through the lower pool of liquid lubricant.

As explained previously adequate lubrication of particularly the bearings 27, is adversely affected in this prior art design by angle of inclination of installation of the housing 11, as well as start-up related issues and by larger exciter apparatus requiring greater levels of lubrication.

The housing 11 of the vibration exciter 10 has lower outwardly extending flanges 32 with a plurality of fastener (bolt) receiving bores 33 along their lengths to allow fastener bolts or the like to secure the vibration exciter 10 to any desire operative position on processing or handling equipment required to be vibrated. The outwardly extending flanges 32 may be strengthened or stiffened by spaced vertical webs 34.

The shafts 22, 23, in use, are drivingly connected to a drive motor (or motors) to rotate the eccentric masses 24 to create a desired vibration regime. Various arrangements are known for achieving this including, but not limited to, a drive motor driving each shaft, a drive motor driving one shaft with rotation being transferred to the other shaft by gearing means including the intermeshing gears 5, 6. Exciter apparatus 10 utilising one shaft, two shafts or more than two shafts are known and aspects of the developments disclosed in this specification will be recognised as applying to such vibration exciters. The above brief description of prior art vibration exciters and parts thereof are not part of the developments of this specification, however, it will be apparent that many of the features described above and disclosed in Figs 1 to 4 can be applied to the developments described below with reference to Figs 5 to 9.

In the drawings of Figs 5 to 9, like features with those identified in the preceding relative to Figs 1 to 4, have been given the same reference numbers. Fig 5 illustrates in longitudinal cross-sectional view, one possible embodiment of a gear arrangement 40 with intermeshing gears 5 and 6. Fig 5 shows the gear arrangement 40 in a typical installed position where the floor or base wall 41 is inclined with the pool 42 of bearing and gear lubrication liquid being located essentially in the lower most (left in the drawing) corner. The intermeshing gears 5, 6 are counter rotating as indicated by arrows 43, 44. The gear 5 is rotating in a counter clockwise direction and the gear 6 is rotating in a clockwise direction. The gear 6 in Fig 5 is illustrated dipping into the main pool 42 of liquid lubricant although the gear 5 is free of any direct contact with the liquid lubricant pool 42. In this configuration a film of liquid lubricant will adhere, as shown by indicator 85, to the teeth of gear 6 and be carried to the gear 5 to contact the teeth of gear 5 and be carried on as indicated at 86. A spray of droplets of liquid lubricant also generally follows the path indicated by arrow 43 such that a small amount of this liquid lubricant is directed towards the internal wall surfaces of side walls 12, 13, end wall 15 and the top cover wall 17 in the regions of the corner zone 85 (Fig 5) . In the corner zone 85 short upraised walls 45, 46, integral with the side wall 13, are posited, that together with the contained portion of the side wall 13, form a first liquid lubricant collector zone 47. The walls 45, 46 are positioned in a V-configuration such that collected liquid lubricant is caused to gravitationally flow to the apex of the V-configuration where the walls 45, 46 converge to approach one another. At this position the walls 45, 46 meet the outer surface of the bearing mounting structure 9. As can be better seen in Fig 6 a groove section 48 is formed in the outer surface of the bearing mounting structure 9, the groove section 48 leading to an axial passage 49 formed through the bearing mounting structure 9. The axial passage 49 opens onto the outer face of the bearing mounting structure 9 inwardly of a closure plate 25, 26. Similar structures to those just described will be also provided on side wall 12.

Again, as best seen in Fig 6, a liquid flow path 50 leads from the first liquid lubricant collector zone 47 to a liquid lubricating pool zone 51 in a bearing mounting cavity 52 located within the bearing mounting structure 9. The liquid lubricating pool zone 51 is maintained by providing a liquid lubricant weir 53 connected to the bearing mounting structure 9 at an inner end of the bearing mounting cavity 52. The liquid lubricant weir 53 may be formed from plate material in the form of a segment where the straight edge of the segment forms the upper weir edge and the lower portions are secured to the bearing mounting structure 9 by multiple fasteners.

If the liquid lubricant builds up in the liquid lubricant zone 51 sufficiently to overflow the weir 53, any such overflow liquid lubricant will simply flow back to the main liquid lubricant pool 42. The flow path 50 includes the groove section 48, the outward extending axial passage 49, and a section 54 generally between the closure plate 25 or 26 and the adjacent bearing 27. The section 54 may be formed as a groove, other recessed zone, or as a passage in the closure plate 25, 26. While the drawings show the various discussed features at one end of the elevated (by installation inclination) shaft 22, similar features will be provided associated with the bearing 27 at the other end of the shaft 22.

The advantage of having a small source of liquid lubricant in the or each elevated bearing 27 liquid lubricant zone 51 is as follows. If operation of the vibration exciter apparatus is ceased temporarily for any reason, at restart up, any elevated bearing 27 would have its own source of liquid lubricant from the zone 51. Without this, the elevated bearings would have to depend on splash lubrication from the main liquid lubricant pool 42. Of course the liquid lubricant in the zone 51 is maintained on continued operation providing continual lubrication to the elevated bearings 27. Of course, it is also possible for the zones 51, upon initial start up, to be intentionally filled with liquid lubricant such that the elevated bearings would have adequate lubrication until the zones 51 can be replenished with liquid lubricant by operation of the bearing lubrication system disclosed herein.

Figures 5 to 9 also illustrate a further preferred aspect of the bearing lubrication system 80. In accordance with this aspect, a second liquid lubricant collector zone 60 is provided associated with the first liquid lubricant collector zone 47. The second liquid lubricant zone 60 includes at least one formed plate member 61 mounted to depend from an inwardly facing surface of the top closure plate or wall 17. The formed plate member 61 has a liquid collector surface 62, to extend axially or transversely relative to the gears 5, 6. Conveniently the formed plate member 61 has an S or Z shape in cross section. The liquid collector or surface 62 is suitably formed to retain liquid lubricant 70 falling onto it or impinging onto it and may also be sloped towards a side wall 12 or 13 of the housing 11. Preferably, the liquid collector surface 62 has an outer end positioned to gravitationally drop liquid lubricant collected onto the first liquid lubricant collector zone 47. Alternatively, any suitably flow apertures or flow recesses may be provided through the liquid collector surface 62, to gravitationally drop collected liquid lubricant collector zone 47. As partly shown in Fig 6, the formed plate member 61 may generally extend transversally across the housing 11 such that liquid lubricant collected on the liquid collector surface 62 may be arranged to flow in opposite outward directions (ie to the left and right in Fig 6) to be collected in oppositely located first liquid lubricant collector zones 47. This arrangement is believed likely to collect more liquid lubricant spray from the gears 5, 6.

The bearing lubrication system 80 as disclosed herein essentially may include the first liquid lubricant collection zone 47, the second liquid lubricant collector zone 60, the flow path 50 and the veering liquid lubricant zone 51.

It will be understood and appreciated by those skilled in this art, that many various and modifications to the features, configurations and arrangements of the disclosed lubrication system are possible and may be made withing the scope of the accompanying claims, particularly having regard to the designs of known vibration exciter apparatus.

Claims

A bearing lubrication system for a gear arrangement including at least one gear carrying shaft supported by at least one bearing mounted in a bearing mounting cavity of bearing mounting means forming part of a housing of said gear arrangement, said gear, in use, being rotatable through a first pool of liquid lubricant carried within said housing, said bearing lubrication system being characterised by:

a liquid lubricant collection zone positioned internally of said housing to collect liquid lubricant dispersed by said gear passing through said first pool of liquid lubricant;

a liquid lubricant weir means closing, at least partially, said bearing mounting cavity, whereby a liquid pooling zone is formed in a lower region of said bearing mounting cavity; and

a liquid lubrication flow path enabling collected liquid lubricant from said liquid lubricant collection zone to flow from said liquid lubricant collection zone to said liquid pooling zone to form in said liquid pooling zone, a second pool of liquid lubricant.
A bearing lubrication system according to claim 1 wherein the bearing mounting cavity of said bearing mounting means includes an external opening closed, in use, by a cover plate member through which said gear carrying shaft passes to a position external of said housing, said liquid lubricant flow path including a first passage section passing from said first liquid lubricant collection zone in an outward direction, the liquid lubricant path further including a downward direction section either between the cover plate member and said bearing or through said cover plate member to be disposed in said bearing mounting cavity.
A bearing lubrication system according to claim 1 or claim 2 wherein said liquid lubricant collection zone includes a first zone section formed by an internal surface of a wall of said housing, and a pair of upstanding wall portions extending inwardly from said internal surface zone, said pair of upstanding wall portions converging towards one another in a V-configuration in a direction generally towards the bearing mounting means, and said liquid lubricant flow means includes a first flow passage leading outwardly through said wall of said housing from a location adjacent an apex of said V-configuration.
A bearing lubrication system according to claim 3 wherein said liquid lubricant collection zone includes a second zone section having a liquid collection plate surface disposed generally axially relative to the gear carrying shaft, said liquid collection plate surface being spaced from said upstanding wall portions of said first zone section and is configured to deliver collected liquid lubricant therefrom to said first zone section.
A bearing lubrication system according to claim 4 wherein said collected liquid lubricant is delivered from an end edge of said liquid collection plate surface.
A bearing lubrication system according to claim 5 wherein the housing of the gear arrangement has opposed side walls with a said bearing mounting means and a said bearing mounted in a said bearing mounting cavity being located in each side wall, said gear carrying shaft passing through a said cover plate member closing each said bearing mounting cavity, said second zone section having a liquid collection plate surface extending axially between positions adjacent to and spaced from said side walls.
A bearing lubrication system according to claim 4 to 5 wherein said second zone section is mounted to an inner surface of a closure lid wall of said housing.
A bearing lubrication system according to any one of claims 1 to 7 wherein the gear arrangement includes at least two said gear carrying shafts, the gears carried intermeshing with one another.
A vibration exciter including a gear arrangement and bearing lubrication system according to any preceding claim the or each said gear carrying shaft also carrying one or more eccentric masses externally of said housing.